As Adolf Hitler continued construction on concentration camps in Europe, 20,000 American Nazis gathered in one of the most iconic venues in the world.

The black and white footage assured below — curated by documentarian Marshall Curry in a 7-minute film, “A Night At The Garden” — is appalling. There’s no added audio commentary or dramatized film editing — the bone-chilling scenes and speeches from the 1939 event speak for themselves.

This, terrifyingly, happened in America:

“A Night At The Garden” premiered in October 2017 on The Atlantic. But the movie, also published on YouTube, went viral on Reddit in February 2018, sparking another wave of attention to the alarming and often forgotten event.

Nearly eight decades later, many of the themes and rhetoric on display are strikingly similar to the political climate of today.

A speaker at the event attacked a biased media and portrayed himself as the main victims : “Ladies and gentlemen, fellow Americans, American patriots, ” he began. “I am sure I do not come before you tonight as a complete stranger. You all have heard of me through the Jewish-controlled press, as a creature with cornets, a cleft hoof, and a long tail.” The crowd laughed.

Much of the event presented overt signs of patriotism : a massive flag of George Washington hung above the stage while dozens of officials marched proudly, American flags held high. The event, let’s not forget, was dubbed “Pro-American.”

Image via “A Night At The Garden”/ YouTube.

The speaker promoted a nostalgic yearn for the past — one undeniably tied to race and power. “We, with American ideals, demand that our government shall be returned to the American people who founded it, ” he yelled to cheers. The event turned violent at one point as well, while the speaker did nothing to soothe tensions, grinning from behind the rostrum as the crowd roared.

“The first thing that struck me was that an event like this could happen in the heart of New York City, ” Curry noted to The Atlantic last year. “Watching it felt like an episode of ‘The Twilight Zone, ‘ where history has taken a different path. But it wasn’t science fiction — it was real, historical footage . It all felt eerily familiar, given today’s political situation.”

“It seems amazing that[ the event] isn’t a stock part of every high school history class, ” Curry said.

But there’s a reason why that is, in agreement with the filmmaker: “This story was likely nudged out of the canon in part because it’s scary and embarrassing. It tells a tale about our country that we’d prefer to forget.”